NBC Bay Area's Stephanie Chuang shows why some are alarmed after a picture of the San Francisco International Airport was included in a publication run by Al Qaeda. (Published Thursday, April 10, 2014)

A stock photo of San Francisco International Airport featured in an international publication – reportedly run by al Qaeda - is sounding off alarms on Capitol Hill, especially as the year anniversary of the Boston Marathon bombings nears.

At a Homeland Security hearing on Wednesday, Rep. Eric Swalwell, D-Dublin, said he was first alerted by a top law enforcement official in the Bay area to the picture of what appears to be the AirTrain at SFO. The caption was what was most alarming, reading in part, “Simply stand up, pack your tools of destruction. Assemble your bomb. Ready for detonation.”

This ad in Inspire Magazine shows an AirTrain, which serves BART and several SFO spots..

The FBI stressed there is no added public safety threat specific to the Bay Area, and that this photo appears to be randomly selected. It is unclear how authorities know that this photo is of the SFO AirTran, but Swalwell's office as well as a TSA agent said they were told it is by "local law enforcement."

Still, Swalwell said the ad deserves attention. It was published in the English-language spring edition of Inspire, which is reportedly an al Queda publication.

“The photo is certainly concerning. It’s calling on al Qaeda members to carry out a terrorist attack,” said Swalwell from Washington D.C. “And a year after the Boston Marathon bombings we should be mindful that rogue individuals inspired by al Qaeda can use household items to carry out these devastating attacks.”

Officials with the FBI, Transportation Safety Administration, and SFO all believe the picture used in the al Qaeda ad was a stock photo, meaning it wasn’t one taken by someone linked to the organization.

Off-camera, one TSA official told NBC Bay Area that the agency believed the ad to be propaganda that just happened to use that backdrop.

Steve Weber, who works at UC Berkeley’s School of Information, specializes in the international and national security. By phone he told NBC Bay Area that it is still something worth taking seriously because propaganda and real recruiting are all the same thing in this environment.

“This is an extremist group for which all those things are the same,” said Weber.

He added that the U.S. government would be able to determine fairly quickly if it was a stock photo or reconnaissance by terrorist, but said if it was the latter, it wouldn’t have been so easily found by Western officials.

Content in the rest of the publication is disturbing. Swalwell said he first saw it, himself, on Wednesday. At a Homeland Security Committee hearing on Capitol Hill prompted by the April 15 anniversary of the bombings at the Boston Marathon, Swalwell brought up concerns about the ad and the publication, which is titled “Inspire.”

“What I’m doing on the Homeland Security Committee is trying to encourage funding for anti-terrorism programs that will better train and equip local law enforcement officials,” Swalwell explained.

It’s training he said was important, pointing to the sniper shooting of the PG&E Metcalf substation almost a year ago as an example of how Bay Area sites are still vulnerable.

It was just after 1 a.m. on April 16, 2013 when snipers took out 17 giant transformers and then disappeared. It was an act former head of the Federal Energy Regulatory Commission had deemed the most significant domestic terrorist attack involving the grid in U.S. history. The FBI has never determined it to be a terrorist attack, but it remains an open investigation.

“[It] still has not been solved and we have no further leads to really truly understand what occurred there,” added Swalwell.

He is hoping the fast-approaching anniversaries of the PG&E substation shooting and Boston Marathon bombings, coupled with the al Qaeda ad using SFO as a backdrop will remind people to always keep their eyes and ears open.

“A terrorist attack is more likely to be stopped because an everyday citizen sees something and then says something.”